1. Field of the Invention
The present invention relates to a hydrogen discharger and an apparatus comprising the same. More specifically, it relates to a hydrogen discharger for discharging only hydrogen from hydrogen-containing gas in a container made from palladium or palladium alloy by heating the container from outside with a heater and to an apparatus comprising the same, for example, an absorption type refrigerating apparatus.
2. Background Art
This type of hydrogen discharger 200 (to be referred to as "first prior art" hereinafter) constituted as shown in FIGS. 11A, 11B, 12A, and 12B is disclosed by Japanese Laid-open Patent Application No. Hei 5-9001. In the following diagrams, parts denoted by the same reference symbols have the same functions as parts having the same reference symbols described in any one of the diagrams.
In FIG. 11A, a gas generator 100 is an apparatus for generating gas 110 containing hydrogen (to be referred to as "hydrogen-containing gas" in the present invention) like an absorption type refrigerator, for example, which will be described hereinafter and for the operation function of which hydrogen is bad.
The hydrogen-containing gas 110 passes through a switch valve 230, is introduced into a hydrogen discharge pipe 201 (to be referred to as "palladium cell" hereinafter) made from palladium or palladium alloy and stored. The cylindrical palladium cell 201 has a closed portion 201A at one end and an open portion 201B at the other end. The hydrogen-containing gas 110 is introduced from the open portion 201B. In this prior art, when the material of the palladium cell 201 is a palladium alloy, the palladium alloy comprises 75% of palladium and 25% of silver.
The valve body 230B of the switch valve 230 is driven by an electric actuator 230A, such as a plunger using a solenoid coil, or a motor to open or close a flow from a passage 231 to a passage 232. The pressure of the hydrogen-containing gas 110 in the palladium cell 201, that is, internal pressure is detected by a pressure detector 235 while the hydrogen-containing gas 110 is introduced into the palladium cell 201 by opening the switch valve 230. When the internal pressure becomes a predetermined pressure, for example, 10,666 Pa, that is, ca. 80 mmHg at this point, the switch valve 230 is closed.
Around the palladium cell 201, an electric heater 240 is formed cylindrical to surround the palladium cell 201 and AC voltage is applied to the electric heater 240 from an AC power source 300 through feeder lines 151 to heat the palladium cell 201. In another prior art, a single rod-shaped heater is arranged next to and parallel to a single hydrogen discharger (not shown).
Only hydrogen contained in the hydrogen-containing gas 110 is permeated to the outside of the palladium cell 201 by increasing the temperature of the palladium cell 201 to 300.degree. C. to 350.degree. C. so that hydrogen which is bad for the operation function of the gas generator 100 can be removed.
The electric heater 240 is a sheath heater formed cylindrical or a heating unit covered with silicon rubber or the like. When the temperature of the palladium cell 201 exceeds 400.degree. C., according to application AC voltage or the size and heat capacity of the palladium cell 201, the thickness of the sheath such as silicon rubber is adjusted to control the temperature.
However, in the above prior art, only heat generated from the inner peripheral surface of the cylindrical electric heater 240 heats the palladium cell 201 and heat generated from the outer peripheral surface of the electric heater 240 is wasted. Therefore, it is difficult to carry out heating for promoting the discharge of hydrogen efficiently.
In the unshown rod-shaped heater, only heat generated from one side surface of the heater heats the palladium cell and heat generated from the other three side surfaces is wasted. Therefore, it is also difficult to carry out heating efficiently.
Meanwhile, the difference of the constitution of FIG. 12A from the constitution of FIG. 11A is that the palladium cell 201 which is a hydrogen discharge pipe is formed cylindrical and bent like letter U so that the hydrogen-containing gas 110 is introduced from open portions 201B at both ends of the U-shaped palladium cell 201. The electric heater 240 is formed oval to increase the discharge surface of hydrogen, that is, the outer peripheral surface of the palladium cell 201 facing the inner surface of the electric heater 240.
Further, an absorption type refrigerating apparatus 500 (shown in FIG. 13, to be referred to as "second prior art" hereinafter) in which the gas generator 100 of the above first prior art is used as an absorption type refrigerator 100A and the hydrogen-containing gas 100 generated inside the absorption type refrigerator 100A is supplied to the hydrogen discharger 200 to be removed is disclosed by Japanese Laid-open Patent Application No. Hei 6-194010.
The absorption type refrigerator 100A is an absorption type refrigerator for carrying out only cooling operation for cooling a required fluid, for example, brine based on the absorption function and evaporation function of an absorption solution, in which only cooling is a load, or an absorption type refrigerator for carrying out heating operation for heating a required fluid, for example, brine based on heat obtained by heating an absorption solution and heat generated by an absorption function in addition to cooling operation, that is, an absorption type cold/hot water apparatus in which both cooling and heating are loads. In the present invention, these are generally called "absorption type refrigerator".
In the absorption type refrigerator 100A shown in FIG. 13, a concentrated absorption solution 102c is sprinkled into an absorber 101 to absorb refrigerant vapor 107c and a diluted absorption solution 102a obtained by cooling absorption heat with cooling water 132 passing through a cooling pipe 101B is heated with a high-temperature regenerator 105 to evaporate it and obtain refrigerant vapor (not shown).
The concentrated absorption solution 102c is obtained by evaporating refrigerant vapor from an intermediate solution 102b by hot evaporated refrigerant vapor in a low-temperature regenerator 111, and also cold water 135 is obtained by sprinkling a low-temperature liquid refrigerant 126a obtained by condensing refrigerant vapor with a condenser 123 from above into an evaporator 126 while storing the liquid refrigerant 126a in a bottom portion of the evaporator 126 to cool brine, for example, water passing through a heat exchange pipe 126B. Thereby, the above cooling operation is carried out.
The refrigerant vapor 107c obtained by evaporating the liquid refrigerant 126a through the absorption of heat from the heat exchange pipe 126B passes through a passage between the evaporator 126 and the absorber 101, enters the absorber 101, and is absorbed into the above sprinkled concentrated absorption solution 102c to become the diluted absorption solution 102a again. Thus, the circulation of the absorption solution and the refrigerant is carried out.
Without circulating the above refrigerant vapor 107c and the liquid refrigerant 126a and cooling with the cooling water 132, the diluted absorption solution 102a obtained in the absorber 101 is heated in the high-temperature regenerator 105 to obtain high-temperature refrigerant vapor and the intermediate solution 102b having an intermediate concentration which are circulated in the absorber 101 and the evaporator 126 to heat brine, for example, water passing through the heat exchange pipe 126B, thereby obtaining hot water 135. Thus, the above heating operation is carried out.
The above cooling operation and heating operation are controlled by a control unit 180. The control unit 180 outputs control signals for controlling, for example, a pump for circulating the absorption solution, the switch valve for opening or closing circulation passages, a heating volume control valve for heating the absorption solution and the like through control processing using, for example, a microcomputer based on operation signals from parts for setting required operation conditions and detection signals obtained by detecting the temperature or the like at each part.
The above absorption solution may circulate in a portion heated at a high temperature, for example, 160.degree. C. Therefore, an absorbing agent contained in the absorption solution, for example, lithium bromide, reacts with a stainless steel material constituting each unit or pipe to generate hydrogen which is contained in the refrigerant vapor 107c. Since this hydrogen and nitrogen and oxygen both of which are leaked in when connection portions of each pipe and unit are interconnected are not condensed by the operation function of the absorption type refrigerator 100A, they are contained in the refrigerant vapor 107c as a gas.
Nitrogen and oxygen do not increase but hydrogen increases in quantity along with the passage of time. Therefore, such uncondensed gas reduces the content of the refrigerant vapor 107c in the absorber 101 and the evaporator 126, thereby reducing the efficiency of the absorption function.
Accordingly, the refrigerant vapor 107c is introduced into a gas/liquid separator 280 from the absorber 101 and the evaporator 126 to be cooled and condensed, whereby uncondensed gas, that is, the above hydrogen-containing gas 110 is separated and supplied to the hydrogen discharger 200 from the passage 231 to be discharged, thereby eliminating the above inconvenience.
Further, the above Japanese Laid-open Patent Application No. Hei 6-194010 also discloses an absorption type refrigerating apparatus 500 (shown in FIG. 14, to be referred to as "third prior art" hereinafter) in which a plurality of the hydrogen discharger 200 shown in FIG. 13 are provided so that the hydrogen-containing gas 110 is introduced into the hydrogen dischargers 200 sequentially to improve the hydrogen discharge efficiency.
In FIG. 14, each passage 231 for introducing the hydrogen-containing gas 110 into each hydrogen discharger 200 from the gas/liquid separator 280 is provided with a switch valve 230, a pressure detector 235 and a relay 250, and the control unit 180 controls to activate the hydrogen dischargers 200 sequentially based on the detection signals of the pressure detectors 235.
Stated more specifically, the switch valve 230 of the passage 231 of the first hydrogen discharger 200, for example, a hydrogen discharger 200 at the highest position is opened to introduce the hydrogen-containing gas 110 into the palladium cell 201 and is closed based on the detection signal of the pressure detector 235 when the pressure of the hydrogen-containing gas 110 in the palladium cell 201 becomes a predetermined value.
Thereafter, the switch valve 230 of the passage 231 of the second hydrogen discharger 200, for example, a hydrogen discharger 200 at the intermediate position is opened to introduce the hydrogen-containing gas 110 into the palladium cell 201 and is closed based on the detection signal of the pressure detector 235 when the pressure of the hydrogen-containing gas 110 in the palladium cell 201 becomes a predetermined value.
Thereafter, the switch valve 230 of the passage 231 of the third hydrogen discharger 200, for example, a hydrogen discharger 200 at the lowest position is opened to introduce the hydrogen-containing gas 110 into the palladium cell 201 and is closed based on the detection signal of the pressure detector 235 when the pressure of the hydrogen-containing gas 110 in the palladium cell 201 becomes a predetermined value.
Then, the control unit 180 controls such that the same operation is repeated from the first hydrogen discharger 200 again. The supply of AC power Vac to the electric heater 240 by the relay 250 is continued for a time period from the time when the switch valve 230 is closed to the time when the pressure of the hydrogen-containing gas in the palladium cell 201 becomes a predetermined value or less.
Since the palladium cell 201 is heated and cooled by heat radiation repeatedly during that time, the hydrogen-containing gas 110 leaks out from a joint between the open portion 201B of the palladium cell 201 and the nozzle portion of the passage 232. Therefore, it has been desired to provide a hydrogen discharger 200 which eliminates the above inconvenience and an apparatus comprising the same, for example, an absorption type refrigerating apparatus 500.
In the hydrogen discharger 200 of the above first prior art, as the palladium alloy used in the palladium cell 201 comprises 25% of silver and the balance consisting of palladium, the material of the palladium cell 201 has such high durability that it is rarely destroyed by heat.
However, palladium cells 201 having different shapes must be produced according to application purpose. When a palladium cell 201 having a complex shape, for example, the shape shown in FIG. 12A, is to be produced, a slightly soft material having high workability is preferably used. When a palladium cell 201 having a simple shape is to be produced, a hard material having excellent durability is preferably used. Therefore, it is necessary to select which material to be used in the palladium cell 201.